1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
#ifndef _GPXE_ATA_H
#define _GPXE_ATA_H
#include <stdint.h>
#include <gpxe/blockdev.h>
#include <gpxe/uaccess.h>
#include <gpxe/refcnt.h>
/** @file
*
* ATA devices
*
*/
FILE_LICENCE ( GPL2_OR_LATER );
/**
* An ATA Logical Block Address
*
* ATA controllers have three byte-wide registers for specifying the
* block address: LBA Low, LBA Mid and LBA High. This allows for a
* 24-bit address. Some devices support the "48-bit address feature
* set" (LBA48), in which case each of these byte-wide registers is
* actually a two-entry FIFO, and the "previous" byte pushed into the
* FIFO is used as the corresponding high-order byte. So, to set up
* the 48-bit address 0x123456abcdef, you would issue
*
* 0x56 -> LBA Low register
* 0xef -> LBA Low register
* 0x34 -> LBA Mid register
* 0xcd -> LBA Mid register
* 0x12 -> LBA High register
* 0xab -> LBA High register
*
* This structure encapsulates this information by providing a single
* 64-bit integer in native byte order, unioned with bytes named so
* that the sequence becomes
*
* low_prev -> LBA Low register
* low_cur -> LBA Low register
* mid_prev -> LBA Mid register
* mid_cur -> LBA Mid register
* high_prev -> LBA High register
* high_cur -> LBA High register
*
* Just to complicate matters further, in non-LBA48 mode it is
* possible to have a 28-bit address, in which case bits 27:24 must be
* written into the low four bits of the Device register.
*/
union ata_lba {
/** LBA as a 64-bit integer in native-endian order */
uint64_t native;
/** ATA registers */
struct {
#if __BYTE_ORDER == __LITTLE_ENDIAN
uint8_t low_cur;
uint8_t mid_cur;
uint8_t high_cur;
uint8_t low_prev;
uint8_t mid_prev;
uint8_t high_prev;
uint16_t pad;
#elif __BYTE_ORDER == __BIG_ENDIAN
uint16_t pad;
uint8_t high_prev;
uint8_t mid_prev;
uint8_t low_prev;
uint8_t high_cur;
uint8_t mid_cur;
uint8_t low_cur;
#else
#error "I need a byte order"
#endif
} bytes;
};
/** An ATA 2-byte FIFO register */
union ata_fifo {
/** Value in native-endian order */
uint16_t native;
/** ATA registers */
struct {
#if __BYTE_ORDER == __LITTLE_ENDIAN
uint8_t cur;
uint8_t prev;
#elif __BYTE_ORDER == __BIG_ENDIAN
uint8_t prev;
uint8_t cur;
#else
#error "I need a byte order"
#endif
} bytes;
};
/** ATA command block */
struct ata_cb {
/** Logical block address */
union ata_lba lba;
/** Sector count */
union ata_fifo count;
/** Error/feature register */
union ata_fifo err_feat;
/** Device register */
uint8_t device;
/** Command/status register */
uint8_t cmd_stat;
/** LBA48 addressing flag */
int lba48;
};
/** Obsolete bits in the ATA device register */
#define ATA_DEV_OBSOLETE 0xa0
/** LBA flag in the ATA device register */
#define ATA_DEV_LBA 0x40
/** Slave ("device 1") flag in the ATA device register */
#define ATA_DEV_SLAVE 0x10
/** Master ("device 0") flag in the ATA device register */
#define ATA_DEV_MASTER 0x00
/** Mask of non-LBA portion of device register */
#define ATA_DEV_MASK 0xf0
/** "Read sectors" command */
#define ATA_CMD_READ 0x20
/** "Read sectors (ext)" command */
#define ATA_CMD_READ_EXT 0x24
/** "Write sectors" command */
#define ATA_CMD_WRITE 0x30
/** "Write sectors (ext)" command */
#define ATA_CMD_WRITE_EXT 0x34
/** "Identify" command */
#define ATA_CMD_IDENTIFY 0xec
/** An ATA command */
struct ata_command {
/** ATA command block */
struct ata_cb cb;
/** Data-out buffer (may be NULL)
*
* If non-NULL, this buffer must be ata_command::cb::count
* sectors in size.
*/
userptr_t data_out;
/** Data-in buffer (may be NULL)
*
* If non-NULL, this buffer must be ata_command::cb::count
* sectors in size.
*/
userptr_t data_in;
/** Command status code */
int rc;
};
/**
* Structure returned by ATA IDENTIFY command
*
* This is a huge structure with many fields that we don't care about,
* so we implement only a few fields.
*/
struct ata_identity {
uint16_t ignore_a[60]; /* words 0-59 */
uint32_t lba_sectors; /* words 60-61 */
uint16_t ignore_b[21]; /* words 62-82 */
uint16_t supports_lba48; /* word 83 */
uint16_t ignore_c[16]; /* words 84-99 */
uint64_t lba48_sectors; /* words 100-103 */
uint16_t ignore_d[152]; /* words 104-255 */
};
/** Supports LBA48 flag */
#define ATA_SUPPORTS_LBA48 ( 1 << 10 )
/** ATA sector size */
#define ATA_SECTOR_SIZE 512
/** An ATA device */
struct ata_device {
/** Block device interface */
struct block_device blockdev;
/** Device number
*
* Must be ATA_DEV_MASTER or ATA_DEV_SLAVE.
*/
int device;
/** LBA48 extended addressing */
int lba48;
/**
* Issue ATA command
*
* @v ata ATA device
* @v command ATA command
* @ret rc Return status code
*/
int ( * command ) ( struct ata_device *ata,
struct ata_command *command );
/** Backing device */
struct refcnt *backend;
};
extern int init_atadev ( struct ata_device *ata );
#endif /* _GPXE_ATA_H */
|
